1. Field of Invention
The present invention relates to a method of forming an integrated circuit, and more generally to a method of forming a semiconductor device.
2. Description of Related Art
MOS is a basic structure widely applied to various semiconductor devices, such as memory devices, image sensors and display devices. The traditional MOS transistor is difficult to scale down due to the limitation of the fabricating process, and a multi-gate transistor with better properties is therefore developed. One example is the fin-type field effect transistor (FinFET) with multiple three-dimensional (3D) fins. The effective channel of the FinFET is disposed not only on the top surface portion but also on the sidewall portion of each fin, so as to greatly increase the channel width.
However, the fins of the FinFET are easy to be deformed by the subsequent processes, thereby reducing the device performance. Therefore, how to prevent the shape of the fins from being deformed by the subsequent processes has drawn great attention in the industry.